The invention discloses an image processing, big data analysis and knowledge base-based internet personal fashion color diagnosis method. The method involves a skin color big data analysis library, a skin color spectrum library, a fashion consultant optimal practice knowledge base, a common clothing color library, a website server, a data receiving unit and a payment unit, wherein the website server comprises a visitor management unit, a file management unit, a color diagnosis unit and a color reporting unit; the data receiving unit, the visitor management unit, the file management unit, the color diagnosis unit and the color reporting unit are connected in sequence; and the color diagnosis unit is connected with the skin color big data analysis library, the fashion consultant optimal practice knowledge base, the skin color spectrum library and the common clothing color library. According to the method, a customer can know own fashion color and style gene attribute, and find a color matching law most suitable for him, so that the shopping time of the customer is saved, the inventory backlog of an enterprise is reduced, and social resource utilization is optimized.